1ABS(3)                     Linux Programmer's Manual                    ABS(3)
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NAME

6       abs, labs, llabs, imaxabs - compute the absolute value of an integer
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SYNOPSIS

9       #include <stdlib.h>
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11       int abs(int j);
12       long int labs(long int j);
13       long long int llabs(long long int j);
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15       #include <inttypes.h>
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17       intmax_t imaxabs(intmax_t j);
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DESCRIPTION

20       The  abs() function computes the absolute value of the integer argument
21       j.  The labs(), llabs() and imaxabs() functions  compute  the  absolute
22       value  of  the argument j of the appropriate integer type for the func‐
23       tion.
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RETURN VALUE

26       Returns the absolute value of the integer argument, of the  appropriate
27       integer type for the function.
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CONFORMING TO

30       SVr4,  POSIX.1-2001,  4.3BSD,  C99.   C89  only  includes the abs() and
31       labs() functions; the functions llabs() and  imaxabs()  were  added  in
32       C99.
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NOTES

35       Trying  to  take the absolute value of the most negative integer is not
36       defined.
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38       The llabs() function is included in glibc since version 2.0, but is not
39       in  libc5  or libc4.  The imaxabs() function is included in glibc since
40       version 2.1.1.
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42       For  llabs()  to  be  declared,  it  may   be   necessary   to   define
43       _ISOC99_SOURCE  or  _ISOC9X_SOURCE  (depending on the version of glibc)
44       before including any standard headers.
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46       GCC handles abs() and labs() as builtin functions.  GCC 3.0  also  han‐
47       dles llabs() and imaxabs() as builtins.
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SEE ALSO

50       cabs(3), ceil(3), fabs(3), floor(3), rint(3)
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54GNU                               2000-12-17                            ABS(3)